use strict;
use warnings;
sub palindrome{
my ($n)=shift;
my ($a,$b);
$b=$a=$n;
return $a if ($a eq reverse $a);
1 while (++$a  != (reverse $a));
1 while (--$b != (reverse $b));
(abs($n-$a)>abs($n-$b))?$b:$a;
}